Triaging a DLL planting vulnerability

DLL planting (aka binary planting/hijacking/preloading) resurface every now and then, it is not always clear on how Microsoft will respond to the report. This blog post will try to clarify the parameters considered while triaging DLL planting issues. It is well known that when an application loads a DLL without specifying a fully qualified path, Windows attempts to locate the DLL by searching a well-defined set of directories in an order known as DLL search order.